This invention relates in general to antifriction bearings and more particularly to an easily assembled package bearing.
The road wheels of automotive vehicles rotate on antifriction bearings that accommodate both axial and radial loads. Typically two single row bearings exist at each wheel and they are organized in opposition so that one takes thrust loads in one direction and the other takes thrust loads in the opposite direction. To this end, each of the two bearings has rolling elements which roll along raceways that are inclined relative to the axis of rotation. The raceways for the one row are inclined opposite to the raceways in the opposite row, this giving the bearings the capacity to take thrust loads in both axial directions.
But the individual components that actually serve to couple the road wheel to the vehicular suspension system must be assembled, and this requires time. Moreover, the assembly procedure usually requires applying grease to serve as a lubricant, fitting seals to retain the grease and protect the bearings from contaminants. Moreover, the bearings usually require adjustment so that they operate at the proper setting--either end play or preload--and this requires skill. If the components also include sensing devices for antilock braking systems, the assembly procedure becomes more complex and time-consuming.
In an effort to simplify assembly operations, automobile and truck manufacturers have turned to package bearings for at least some of the road wheels, both driven and nondriven, of their vehicles. The typical package bearing has two rings which rotate relative to each other by reason of rolling elements interposed between them in two rows. One of the rings fits to the suspension system of the vehicle to which it is secured with bolts, while the other has the road wheel attached to it with nuts turned down over threaded studs. Thus, the whole assembly procedure essentially reduces to bolting components together.
The assembly problems which the automotive manufacturers avoid, bearing manufacturers assume, but with less intensity. Certainly, assembling a package bearing on an assembly line dedicated to such bearings is a good deal easier than undertaking the assembly as part of the overall assembly procedure for the automobile. Moreover, the critical adjustment occurs in an environment which lends itself to considerably more control and precision. But still many packaged bearings or bearing assemblies of current manufacture contain numerous parts and are in their own right difficult to assemble and adjust.
Apart from that, antilock brake systems rely on sensors at the individual wheels and these sensors monitor encoder rings which rotate with the wheels. Often the sensors and encoder rings are exposed and thus more likely to be damaged by rocks, water and road chemicals.
The present invention resides in a packaged bearing assembly that is easily assembled and subsequently installed on an automotive chassis. It also resides in a bearing that has the capacity to monitor angular velocity and includes an encoder ring which is located within the bearing, and is passed over one of the raceways during the assembly of the bearing. To further facilitate assembly one of the rows of rollers is confined by a cage which has breaks in one of its end rings, and these breaks enable the cage to expand as the rollers and cage pass over the large end of the raceway along which the rollers operate. The bearing also has a nonintegral rib ring along one of its raceways, and this ring forms a sealing surface. The invention further resides in the process for assembling the package bearing. The invention also consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed.